Reaction force exposure for tightening tool users : A psychophysical based experimental study of electric right-angle nutrunners

• Reaction forces from nutrunner tools constitute a risk of developing MSDs. However, recommendations for sustainable reaction force levels are lacking. The aim of this study was to inform recommendations regarding reaction load exposures from right-angle nutrunners. Through a psychophysics approach, experienced assembly workers subjectively assessed reaction loads when using a nutrunner in six combinations of tool tightening strategy, work-pace and screw-joint stiffness. Electromyography, tool and joint parameters were measured. Regardless of tightening strategy, joint stiffness and work-pace combinations, no large differences in acceptable tightening torque, peak reaction force, and handle displacement were observed. However, acceptable jerk and impulse differed substantially between the TurboTight (R) (high-acceleration) and QuickStep (R) (conventional) tightening strategies. Although the TurboTight (R) strategy overall showed reduced peak muscular activities compared to the QuickStep (R), the participant-rated acceptable torque levels were similar, plausibly due to TurboTights' high jerk levels. Jerk and impulse are hypothesized to influence the perception of reaction loads.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Produktionsteknik, arbetsvetenskap och ergonomi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Production Engineering, Human Work Science and Ergonomics (hsv//eng)

Nyckelord

Assembly work

Power tools

Electromyography

Ergonomics assessment

Publikations- och innehållstyp

ref (ämneskategori)

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